If you used a Visa, MasterCard or Diners Club card for foreign purchases between 1996 and 2006, you may have overpaid, thanks to hidden surcharges the credit card companies added to their fees. Now a $336 million class action settlement allows you to get some of that money back if you file a claim before May 30. Refunds vary, depending on how much money and time you spent out of the country. They range from $25 for purchases of less than $2,500 up to 3 percent of estimated or documented purchases made during extensive travel. For details and claim forms, go to www.ccfsettlement.com or call 1-800-945-9890.